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Examiner EX "A W RE mm s Referenue BEST AVAILABLE COPY 0 1935- w. F.GROENE CHUCKING DEVICE Original Filed Aug. 6, 1928 4 s t -s t 1 INVENTOR. PM /A MFG/PaE/VE.

ATTORNEYS.

Cross Reference 04. iumumi EE mm Gm I Fm m We Original Filed Aug. 6,1928 4 Sheets-Sheet. 2

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ATTORNEY-S.

81 Tum-m6 Cross Reference Emma 7 Oct. 22, 1935. w F GROENE Re. 19,730

CHUC- KING DEVICE Original Filed Aug. 6, 1928 4 Sheets-Sheet, 3

INVENTOR.

ATTORNEYus.

brass Reference 82. TURNlNG 4 Sheets-Sheet 4 l N VEN TOR Wk 4MMFG/PaEA/E.

A TTORNEYS.

Reissues! Oct. 22, 1935 UNITED STATES PATENT OFFICE CHUCKING DEVICEOriginal No. 1,878,130, dated September 20, 1932, Serial No. 297,881,August 6, 1928. Application for reissue September 18, 1934, Serial No.

22 Claims.

My invention relates to the manufacture of crank shafts, and moreespecially to the accurate turning, in a rapid and economical manner,the cylindrical bearing portions of such shafts, as for 5 example thepin bearings thereof.

The general object of my invention is to in crease the accuracy offinish in such turning; objects subsidiary thereto being especially firmholding of the work piece in chucking appara- 0 tus, accurate locationand maintenance of location of the work piece in the chucking apparatus,freedom from torsional distortion or twisting of the piece in chucking,and rapid production while meeting all of these requirements.

In applying power operated chucking jaws at both endsor at an unclampedend of a crank shaft in a lathe, a very critical situation arises whenthe portions of the crank shaft engaged by the jaws are out of accurateradial angle to go the axis of the shaft. The result is to twist theshaft, and to hold it in twisted position. durins the lathe operations,so. that the turning of" the pins." of the shaft will not be accurate,when the shaft springs back upon being released.

Among other invention con;

' templates the atbqthendsoi the of locating faces or spqts' s'nd'thechucks themselves are equippediitfifl if cooperates with a; 1 "f 3Qlocating races terminirl the the? sssiniiaws' thechucksus.

n jaws which are provides as every strong the wedging rode jppcr'ate'the iaws have shaped faces so as to enable the wedges tofmove the jawsinto position by a short movement and then tighten the Jaws by acontinued a t at a iessor-wedging angle.

I accomplish my objects by those methods, and by those provisions, both.to the work piece and the novel chucking apparatus, as willhereinai'terhemorespecificallypointedoutand claimed.

In the drawings:

Figure 1 is a front elevation of a chucking device embodying myinvention.

50 Figure 2 is a vertical longitudinal section on the line 2-2 of Fig.1.

Figure 2a illustrates the left end of the cylinder omitted from Fig. 2for lack of space.

Figure 3 is a horizontal longitudinal section on sit the lined-I 0111s.1.

Figure 4 is a vertical section on the line 4-4 of Fig. 2.

Figure 5 is a detail side elevation of one of the jaw operating rods.

Figure 5a is a detail front elevation of one 01 5 the chuck jaws.

F ure 6 is a side elevation 0! a crank shaft work piece in anincompleted stage according to my improved method.

Figure 6a. is an enlargement or a left end part 10 of the work piece asshown in Fig. 6, including the representation of a part of abutmentmeans locating the piece according to my invention.

Figure 7 is a vertical cross section on the line ll of Fig. 6a., theabutment means at opposite 15 sides being indicated, in their relationto the work piece, in broken lines.

Figure 8 is a. similar view illustrating a modiiication oi the workpiece, and by broken lines indicating, in their relation to thismodified work go piece, the abutment means at opposite sides.

I have'illustrated no parts of the lathe, but one of the chucks. It willbe understood that like chucks may be used at both head and tail stockor the lathe. a;

The chuck body I is shown separately from its mounting and operatingparts, but it will be understood that the body will be Journaled at 2,and equipped with a driving gear at 3. The power means for the chuckcomprises an air cylinder 4 m with its piston 5, and a coaxial aircylinder 8 of smaller bore, with its piston l. The piston rod 8 of thepiston 5, extends through the piston I, and is provided with anextension 9. The piston 1 has a tubular extension III which carries a 3ggland tor packing the rod 8, and a tubular piston rod H, secured to theextension Ill, surrounds the portion 9 of the inner piston rod. Theportion H has a sleeve l2 fast thereon, which is keyed at l3 to slide inthe chuck body without roo tation therein.

The chuck is illustrated as in engagement with acrankshaftA (Flgs.6and7)havlngtheflange end it, a line bearing i5, and a check or web ii. Inpreparing the shaft for turning, it is placed in g a milling machine,and locating faces B, B are cut in the web It, and also in exactalignment therewithlocating faces C, C are cut in the web it at theother end 01 the shaft. Instead of cutting away part of the webs, theymay be made so with lugs D, D thereon, as shown for the web li in Figure8, and then the outer faces of the lugs are milled in perfect alignmentend for end oi the shaft.

In the outer end portion is of the chuck body I which is U-shaped topermit the shaft to be dropped therein, is a hardened centering andbearing plate I! on which the end line bearing of the crank shaft rests.Located on a ledge lb 5 on the body portion la, is a hardened abutmentor locating block I8 which engages one of the locating faces on the webof the shaft. To cooperate with this fixed abutment which is arrangedfor the particular shaft to be employed, I 10 provide a clamping andpositioning arm l9, which is pivoted on a pin 20 in the chuck body, andpressed by a spring 2| away from engaging position. This arm has a wedgeface 22, on the side of its free end part facing from the work, and itsposition is such that its face toward the work engages the otherlocating face on the shaft Web.

To operate the arm I9 I employ the outer piston rod II, and provide asliding bar 23, which bar moves in a groove in the chuck head and has awedge face to coact with the face 22 on the arm Ill.

The bar 23 has a slot 25 therein, through which a lever 26 passes, saidlever having its outer end 25 pivoted at 21, and having an enlargedrounded middle portion 28 which engages the walls of the slot. The lever20 has a rounded knob 29 at its inner end.

In a channel in the sleeve I2 on the outer pis- 30 ton rod H, a bar 30is mounted and pinned as at 3!. 'lzhe bar has a bifurcated end 32, theopening 33 of which engages over the knob 29.

When, then, the piston I is moved to right or left, the tubular rod ll,through the medium 35 of the sleeve thereon, reciprocates the bar 30.

The bar rocks the lever 26, which moves the bar 23, said bar actuatingthe locating arm by a wedging action. It should be noted further thatthe piston I and its cylinder are of smaller bore than the other pistonand cylinder, so that they operate ahead of the chucking jaw operatingparts.

The chucking jaw elements of my device consist of a pair of heavypartial discs 84, which rest in semi-circular recesses 35 in the chuckhead la. The jaws are pivoted at 36, and their peripheries are curved onthe pivots as a. center, and engage as a bearing in the recesses 35.Springs 31 mounted in the chuck head and secured to the discs 31, tendto hold the discs in non-engaging position with the work. Non-engagingposition is indicated at dotted lines 38 (Fi 1).

A pair of sliding pins 38 are mounted in the chuck head and body andhave ends which are specially faced to engage the wedge faces H on theback ends of the law discs. There are on each pin a slanting face 4|!and a succeeding more slanting face Ila, succeeded by additional 99bevels 42 at considerably less angles than the bevels III, 400, so thatwhen the pins are advanced they first quickly wedge the jaws against thework and then the faces 42 come into engagement to provide the finaltight contact. The 63 wedge faces or bevels are curved so as tocompensate for the arcuated movement of the jaws.

As will be noted, the pins 39 are advanced by a mechanism which has anequalizing action, and while the sharper wedging angles are in play thisequalizing action takes place. The lesser angled faces 42 are such,however, that a great pressure on the work itself will not result inwedging the pins away, whereas with the sharper angles, this might bepossible due to the equalizer system,

79 which is free to respond to differential pressure.

An equalizer yoke 43 is used to operate the jaw wedging pins, and isprovided with circular knobs at its ends to engage the notches M in thepins. To mount the equalizer yoke and operate it, the outer end of theinner piston rod 9 is provided 5 with a shoe 4!; the rod and the shoeboth being slotted as at 46. The yoke has a projection or lug 41 thereinwhich extends into the slot and a pivot pin 48 holds the shoe and theyoke in pivotal relation to the end of the rod. The yoke is thus 10 freeto pivot on the piston rod and within the notches of the wedging pins,whereby its equalizing function is accomplished. The yoke is formed witha hole 49 at its central portion, said hole being larger at its outerends, and extend- 15 ing through the lug, where it is tapped to receivea bolt 50. The pivot pin has a hole in it which is engaged by the tip50a of this bolt, thus holding the pivot pin in position. A locatingpiece Si in the form of a cup lies over the end of the 20 bolt in theenlarged outer end of the hole 49, and is engaged by a spring 52, whichprojects it forward.

As stated, I have not illustrated an entire lathe.

It will be understood that a device such as de- 55 scribed may be usedat both ends of the shaft and both operated simultaneously, which can bedone without danger of twisting the shaft. The two chucks will, as isusual, have a common driver so that their relative positions remain uniaform at all times.

To operate the chucks air or other fluid under pressure is admitted toand exhausted from the two piston cylinders for each chuck through ports53 and 54, in an axial shaft, which cooperates as with the usualmanifold sleeve. The two cylinders are in one casting with common posts.I have shown a needle valve at 55 to vary the action of the innercylinder, the piston of which is to advance more rapidly than the otherpiston, 40 as has been noted.

The air admitted through the port shaft and its manifold supplies thepressure whereby the two pistons of the chucks are advanced or retraetedserving to locate and clamp a crank shaft 4; in' place. The locatingdevices engage the ends of the crank shaft ahead of the jaws andcontinue to hold them while the jaws are being applied. The Jaws beingapplied by an equalizer will adjust themselves. a

A crank shaft is set into the chucks with its webs rotated so that thelocating faces rest against the locating abutments II, and air appliedto the cylinders with the result of locating the shaft under pressure,while the main jaws are rocked It or rotated into engagement.Inequalities in the crank shaft web will be allowed for by the equalizerbar.

I have designed the chuck now fully described for, use with crank shaftlathes which are ar- U ranged to turn all of the pins of the shafts atonce and find that it is very positive and accurate in its action. Thefluid pressure may be turned on and left on throughout the operation,and if it is turned off after the wedges have been fully advanced, thegrip of the jaws will not give way.

The method of forming locating faces on the webs of a shaft which is tobe clamped in place by power, using clamping means for engaging 70 thelocating faces, is subject to considerable variation. It has solved aproblem in connection with high capacity production of crank shafts andhas enabled me to make possible the very rapid mounting of the crankshafts with an 7s accuracy which has been entirely prearranged and withno adjustments whatever.

By limiting the extent of the finished areas or locating spots on thesides of the webs, for

5 abutment with correspondingly limited areas of abutment means of thechuck, it is possible to attain a maximum accuracy of relation of theseparts to each other, and to the proper axis of each cylindrical part ofthe work piece, and to lo the abutment areas of the chuck. These are thelocation means transverse to the web, or, as termed, the indexing means.Having the abutment for location in the general direction of length ofthe web, as for example at centering 15 plate ll, intermediate of thediametral ends of the web, also affords better accuracy than contactwith a more outlying portion of the shaft. This, and the limitation ofarea of locating spots, makes the work independent of any shape that 20the webs may have.

I am thus able to chuck the pieces more rapidly in accordance with thedemands of large scale production; yet without exceeding the limits ofclose finish on the portions to be turned; and

25 without torsional distortion and the inaccuracies resulting therefromas before mentioned; and with a maximum of security of holding andmaintenance of location of the work piece in the chucking device, owingto the limited areas of 30 the mutually engaging spots and abutments.The aggregate result, due to the nature of the novel partially finishedforging when chucked, and due to the improved method of chuckingpermitted by the apparatus, is a more accurately 85 finished, and fasterand more economically produced crank shaft.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

40 1. In a chucking device for crank shafts, fluid power actuatingmeans. a wedging element operated thereby, a fixed locating abutment forengaging a web of such shaft, and movable means actuated by the wedgingelement and serving to 45 force said web against the abutment, andthereby to clamp said web from opposite sides thereof.

2. In a chucking device, the combinationdl power actuated chucking jawsto engage a web of a crank shaft, of means for locating the web- 50 ofsaid shaft comprising a rest for a journal or pin of the shaft. anabutment to engage the web of the shaft adjacent said journal or pin,

and a clamping member positioned to engage said web opposite to theabutment, and power 55 means for actuating said clamping member.

3. In a chucking device, the combination of power actuated chuchng jawsto engage a web of a crank shaft, of means for locating the web of saidshaft comprising a rest for a journal or pin of the shaft, an abutmentto engage the web of the shaft adjacent said journal or pin, and aclamping member positioned to engage said web opposite to the abutment,and power means for actuating said clamping member, said power 55actuating means timed to operate in timed relation with the poweractuated jaws.

4. In a chucking device, the combination of power actuated chucking jawsto engage a web of a crank shaft, of means for locating the web 7 ofsaid shaft comprising a rest for a journal or pin of the shaft, anabutment to engage the web of the shaft adjacent said journal or pin.and a clamping member positioned to engage said web opposite to theabutment, and power means for 76 actuating said clamping member, saidpower actuating means being separate from the operator of the jaws.

5. In a chucking device, the combination of power actuated chucking jawsto engage a web of a crank shaft, of means for locating the web of saidshaft comprising a rest for a journal or pin of the shaft, an abutmentto engage the web of the shaft adjacent said journal or pin, and aclamping member positioned to engage said web opposite to the abutment,and power means for actuating said clamping member, said power actuatingmeans comprising a pressure driven piston and rod, a pivoted memberrocked thereby, and a wedging bar moved by the pivoted member andengaging the clamping member.

6. In a chucking device, a chuck head, circular recesses therein atopposite sides of an opening to receive the work, jaws pivotally mountedand having circular edges which engage the recesses as a journal, andmeans for positively moving said jaws on their pivots.

7. In a chucking device, a chuck head, circular recesses therein atopposite sides of an opening to receive the work, jaws pivotally mountedand having circular edges which engage the recesses as a journal, andmeans for positively moving said jaws on their pivots, said meanscomprising wedge members slidably engaging the Jaws, and power means foroperating the wedge members.

8. In a. chucking device, a chuck head, circular recesses therein atopposite sides of an opening to receive the work, jaws pivotally mountedand having circular edges which engage the recesses as a journal, andmeans for pivotally moving said jaws, said means comprising wedgemembers slidably engaging the jaws, and power means for operating thewedge members including an equalizer bar.

9. In a chucking device, the combination of jaws movable into and out ofposition to engage the work, of power means including an equalizerelement, wedging pins to actuate the jaws, said pins driven by theequalizer element, the wedge faces of the pins having a primary sharpincline and a terminating or final incline at a lesser angle.

10. In a chucking device, the combination of a frame, of pivoted jaws insaid frame for engaging the work, power means including an equalizerelement, wedging pins to actuate the jaws, said pins driven by theequalizer element, the wedge faces of the pins formed on an arc andhaving a primary sharp incline and a terminating or final incline at alesser angle.

11. In a chucking device, a chuck head, circu- 5 lar recesses therein atopposite sides of the opening to receive the work. jaws pivotallymounted and having circular edges which engage the recesses as ajournal, and means within the chuck acting directly on the jaws.positively moving said jaws on their pivots.

12. In a chucking device for crank shafts, loeating abutments, one fixedand another movable to and from the one, a wedge having an operativemovement for moving said other abutment toward the one abutment, andmeans for applying fluid under pressure to cause said operative movementof said wedge.

13. In a chucking device for crank shafts, sets 7 of locating abutments,one fixed and another movable to and from the one, in each set, wedgeshaving operative movements for moving said other abutment toward the oneabutment in the respective sets, and means for applying fluid un- 15die! prmsure to cause said operative movements of said wedges.

M. In a. chucking device for crank shafts, sets of locating abutments,one fixed and another movable to and from the one, in each set, wedgeshaving operative movements for moving said other abutment toward the oneabutment in the respective sets, and means for applying fluid underpressure to cause said operative movement of each wedge, whereby onemovable abutment is moved in advance of another.

15. In a chucking device, the combination of a power actuated chuckingjaw to engage a portion of a crank shaft near one diametral end of a webthereof, of means for locating the shaft in the device for turning acylindrical portion thereof, comprising a rest engaging a predeterminedarea of said shaft between said jaw-engaged portion and the center ofthe cylindrical portion that is to be turned, abutment means to engage apredetermined minor side area of the web near the opposite end of theweb, and a member positioned to engage a predetermined minor oppositeside area of said web near its opposite end, the engagement with saidminor side areas of the web being effected independently of the poweractuation of the chucking jaws, and irrespective of the shape of themajor portion of the web.

16. In a chucking device to hold a crank shaft for turning a cylindricalportion of the shaft adjacent to a web of the shaft, a chuck body,abutment means on said body to engage a finished area of the shaft whichlies intermediate of the diametral end limits of the web, to properlylocate the cylindrical portion in the device along the length of theweb, spaced abutment means on said body, of limited extent to engageonly minor flnished areas of opposite sides of the web, to properlylocate said cylindrical portion in the devicealong a line transverse tothe web, irrespective of the shape of the major portion of the web, andmeans to hold the device and the shaft together with said shaft areasand abutment means in effective location-maintaining contact.

17. In a chucking device to hold a crank shaft for turning a cylindricalportion of the shaft adjacent to a web of the shaft, a chuck body,abutment means on said body to engage afinished area of the shaft whichlies intermediate of the diametral end limits of the web, to properlylocate the cylindrical portion in the device along the length of theweb, spaced abutments on said body, each with a side of limited extentto engage only minor finished areas or! opposite sides of the web toproperly locate said cylindrical porthan in the device along a linetransverse to the web, irrespective of the shape of the major portion ofthe web, said device comprising abutment supporting portions within thechuck body, engaging the oppoflte sides of the respective abutments,directly resisting displacement of the several abutments in abuttingdirection and also in direction at a material angle to said abuttingdirection.

18. In a chucking device for holding a crank shaft by engagement withweb portions thereof spaced longitudinally thereof, to hold the shaftsubstantially free from torsional distortion, for turning cylindricalportions of the shaft, chuck bodies mounted and connected forsynchronous rotation, each having abutment means thereon to engagerespective finished areas of the shaft which lie intermediate thediametral end limits of the shaft webs, to properly locate thecylindried portions in the device along the lengths of ishing an area 0dthe shaft which lies intermealong lines transverse to the respectivewebs, irs respective of the shape of the major portions of the webs, andmeans associated with the respective chuck bodies to hold the bodies andthe shaft together with said shaft areas and shutment mans in effectivelocation-maintaining 1. contact.

19. The method of chucking a. crank shaft for machining a cylindricalportion and adjacent face of a web of the shaft, which comprisesfindiate the diametral end limits of the web, to present a locating facein the direction of the length of the web, in a definite relation to aproper axis of said cylindrical portion, finishing areas of oppositesides of the web which are limited in extent to minor portions of thesides of the web, to present locating faces oppositely outwardtransversely of the web in a definite relation to said proper axis,irrespective of the shape of the maior portion of the web, andsupporting the thus 8| partially finished shaft in a suitable chuckingdevice by definitely located abutment means of the device presentingabutment areas to the respective finished areas of the shaft, whichabutment areas correspond in disposition and limited ex- 30 tent to thedispositions and extent of the respective finished areas of the shaft.

20. The method of chucking a crank shaft for machining cylindricalportions and adJacent faces of webs of the shaft, by engagement withanll gularly alined webs of the shaft spaced longitudinally thereof,which comprises finishing areas of the shaft which lie intermediate ofthe diametral end limits of the webs, to present locating faces in thegeneral direction of the lengths of the webs, do in a definite relationto a proper axis of each cylindrical portion, finishing minor areas ofthe opposite sides of the respective webs in a definite relation to eachother and to said proper axis of each cylindrical portion, irrespectiveof the shapes of 4.5 the major portions of the webs, and supporting thethus partially finished shaft in suitable synchronously rotatable chuckbodies by definitely located abutment means of the bodies presentingareasto the respective finished areas of the shaft, 60 which abutmentareas correspond in disposition and limited extent to the dispositionsand extent of the respective finished areas of the shaft.

21. As a novel article in an incomplete stage of a novel method ofmanufacture of the completso ed article, a work piece for forming acrank shaft, comprising a cylindrical portion and a web with I. faceadjacent to the cylindrical portion, said work piece being prepared forchucking to turn the cylindrical portion and face, in that it is '0provided with a finished area lying intermediate the diametral endlimits of the web in a definite relation to a proper axis of saidcylindrical portion, along the length of the web, and with finishedareas on opposite sides of the web which on are limited in extent tominor portions of said sides of the web, in a definite relation to theproper axis of said cylindrical portion along a. line transverse to theweb, the limited extent of said areas permitting proper centering of thework 70 piece for machining the cylindrical portion and face, byengagement with suitably arranged abutment means on a chucking device,and irrespective of the shape of the major portions of the web.

22. As a novel article in an incomplete stage 1 of a novel method ofmanufacture of the completed article, a work piece for forming a crankshaft, comprising cylindrical portions and webs with laces adjacent therespective cylindrical portions, said piece being prepared for chuckingto machine the cylindrical portions and faces, in that it is providedwith finished areas near respective spaced angularly alined webs, lyingintermediate of the diametral end limits of the webs in a definiterelation to a proper axis of each cylindrical portion along the lengthsof said webs, and with finished areas on opposite sides of each of saidwebs which are limited in extent to minor portions of said sides 01'said webs, in a definite relation to each other and to the proper axis01' each cylindrical portion along lines transverse to said webs, thelimited extent of said areas.permitting the accurate relation of thoseof said areas that are on webs spaced longitudinally of the work piece,for mounting the work piece, substantially free of torsional distortionand properly centered for machining the cylindrical portions and faces,by engagement with suitably arranged abutment means on respectivesynchronously rotatable chucking device, and irrespective of the shapesof the major portions of the webs.

WILLIAM F. GROENE.

